LiOtBu-promoted stereoselective deconjugation of ,-unsaturated diesters probed using density functional theory

We report the isomerisation of alpha,beta-unsaturated diesters to thermodynamically less favourable beta,gamma-unsaturated carbonyl compounds in the absence of strongly basic anhydrous or photochemical conditions. Stereoselective deconjugative isomerisation provides E-selective beta,gamma-unsaturated diesters via an enolate intermediate generated in situ from alpha,beta-unsaturated diesters with high yield and stereoselectivity. Based on density functional theory calculations, the origin of the E-selective deconjugation pathway from conjugated compounds has been elucidated.